Naslov
Petrology and first U-Pb Zircon Age of Metarhyolite from the Vranica Mt., The Mid-Bosnian Schist Mountains

Autori
Garašić, Vesnica ; Jurković, Ivan ; Lugović, Boško ; Hrvatović, Hazim

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Knjiga sažetaka - Abstracts Book / Horvat, Marija ; Wacha, Lara - Zagreb : Hrvatski geološki institut, 2015, 95-96

Skup
5. Hrvatski geološki kongres s međunarodnim sudjelovanjem - 5th Croatian geological congress with international participation

Mjesto i datum
Osijek, Hrvatska, 23.09.2015. - 25.09.2015

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
metarhyolite; petrology; U-Pb zircon age; Gondwana margin

Sažetak
The Vranica Mt. belongs to the allochthonous Paleozoic metamorphic complex of the Mid Bosnian Schist Mountains (MBSM), incorporated within the Internal Dinaride. Paleozoic metamorphic complex of MBSM consists of Variscan metasediments, metavolcanics, limestones, dolomites and Permian post-Variscan formations (Hrvatović, 2006). The aim of the study is to determinate Pb-U zircon-age of the metarhyolite, regarded as being Silurian (Hrvatović, 2006) to Permian (Jurković & Majer, 1954). The metarhyolite samples shaw blasto-porphyritic texture and contain coarse K-feldspar, albite and embayed quartz phenocrysts in the finegrained matrix consisting mostly of quartz, fengite and albite. Zircone, rutile and apatite are accessory phases. The geochemical characteristics of major elements point to the calc-alkaline and peraluminous affinity of magma and the trace element concentrations normalized to chondrite composition show negative Ba, Nb-Ta, Sr and Ti anomalies, features being typical for the magmas originating at the active continental margin. The last growth stage of zircon grains gave a concordia magmatic age of 463±4 Ma (Th/U = 0, 27-0, 56). The geochemical features of the calc-alkaline peraluminous metarhyolite from Vranica Mt. are considered to indicate a partial melting of crustal source in subduction related tectonic setting. The metarhyolite plots into the field of collisional granites defined by Maniar & Piccoli (1989) and could represent a fragment of an Ordovician suture zone developed at the Gondwanan margin after an Ordovician orogenic event evolved from an active margin setting to collision during a short time.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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